function file_get_file_references

Retrieves a list of references to a file.

Parameters

Drupal\file\File $file: A file entity.

$field: (optional) A field array to be used for this check. If given, limits the reference check to the given field.

$age: (optional) A constant that specifies which references to count. Use FIELD_LOAD_REVISION to retrieve all references within all revisions or FIELD_LOAD_CURRENT to retrieve references only in the current revisions.

$field_type: (optional) The name of a field type. If given, limits the reference check to fields of the given type. If both $field and $field_type is given but $field is not the same type as $field_type, an empty array will be returned.

Return value

A multidimensional array. The keys are field_name, entity_type, entity_id and the value is an entity referencing this file.

Related topics

File

drupal/core/modules/file/file.module, line 1568

Defines a "managed_file" Form API field and a "file" field for Field module.

Code

function file_get_file_references(File $file, $field = NULL, $age = FIELD_LOAD_REVISION, $field_type = 'file') {
  $references =& drupal_static(__FUNCTION__, array());
  $field_columns =& drupal_static(__FUNCTION__ . ':field_columns', array());

  // Fill the static cache, disregard $field and $field_type for now.
  if (!isset($references[$file->fid][$age])) {
    $references[$file->fid][$age] = array();
    $usage_list = file_usage()
      ->listUsage($file);
    $file_usage_list = isset($usage_list['file']) ? $usage_list['file'] : array();
    foreach ($file_usage_list as $entity_type => $entity_ids) {
      $entity_info = entity_get_info($entity_type);

      // The usage table contains usage of every revision. If we are looking
      // for every revision or the entity does not support revisions then
      // every usage is already a match.
      $match_entity_type = $age == FIELD_LOAD_REVISION || !isset($entity_info['entity_keys']['revision']);
      $entities = entity_load_multiple($entity_type, $entity_ids);
      foreach ($entities as $entity) {
        $bundle = $entity
          ->bundle();

        // We need to find file fields for this entity type and bundle.
        if (!isset($file_fields[$entity_type][$bundle])) {
          $file_fields[$entity_type][$bundle] = array();

          // This contains the possible field names.
          $instances = field_info_instances($entity_type, $bundle);
          foreach ($instances as $field_name => $instance) {
            $current_field = field_info_field($field_name);

            // If this is the first time this field type is seen, check
            // whether it references files.
            if (!isset($field_columns[$current_field['type']])) {
              $field_columns[$current_field['type']] = file_field_find_file_reference_column($current_field);
            }

            // If the field type does reference files then record it.
            if ($field_columns[$current_field['type']]) {
              $file_fields[$entity_type][$bundle][$field_name] = $field_columns[$current_field['type']];
            }
          }
        }
        foreach ($file_fields[$entity_type][$bundle] as $field_name => $field_column) {
          $match = $match_entity_type;

          // If we didn't match yet then iterate over the field items to find
          // the referenced file. This will fail if the usage checked is in a
          // non-current revision because field items are from the current
          // revision.
          if (!$match && ($field_items = field_get_items($entity, $field_name))) {
            foreach ($field_items as $item) {
              if ($file->fid == $item[$field_column]) {
                $match = TRUE;
                break;
              }
            }
          }
          if ($match) {
            $references[$file->fid][$age][$field_name][$entity_type][$entity
              ->id()] = $entity;
          }
        }
      }
    }
  }
  $return = $references[$file->fid][$age];

  // Filter the static cache down to the requested entries. The usual static
  // cache is very small so this will be very fast.
  if ($field || $field_type) {
    foreach ($return as $field_name => $data) {
      $current_field = field_info_field($field_name);
      if ($field_type && $current_field['type'] != $field_type || $field && $field['id'] != $current_field['id']) {
        unset($return[$field_name]);
      }
    }
  }
  return $return;
}